Johnson, R. R. (1976). Elementary statistics (2nd ed.). Duxbury.
Chicago Style (17th ed.) ZitazioaJohnson, Robert R. Elementary Statistics. 2nd ed. Massachusetts: Duxbury, 1976.
MLA (9th ed.) ZitazioaJohnson, Robert R. Elementary Statistics. 2nd ed. Duxbury, 1976.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.